Cartridge and image forming apparatus

Abstract

A cartridge detachably mountable to a main assembly of an image forming apparatus includes a photosensitive drum; a discharging path for permitting movement of a developer removed from the drum, the discharging path including a developer discharge opening and a movable portion through which the developer is movable and which is movable between a retracted position in an upstream side with respect to a developer moving direction through the discharge opening and a advanced position in a downstream side with respect to the developer moving direction; and a sealing portion for closing the discharging path by contacting the movable portion at a position different from that of the discharge opening.

What is claimed is: 
     
       1. A cartridge comprising:
 a casing including a chamber; 
 a photosensitive drum rotatably supported by the casing, a part of the photosensitive drum being disposed inside of the chamber; 
 a pipe in fluid communication with the chamber, the pipe including an opening configured to communicate the chamber with outside of the cartridge, the pipe being movable relative to the casing between a first position and a second position such that the opening of the pipe is disposed closer to the photosensitive drum when the pipe is in the first position than when the pipe is in the second position; and 
 a seal configured to seal a gap between the pipe and the casing when the pipe is in the first position. 
 
     
     
       2. A cartridge according to  claim 1 , wherein the opening is disposed at a downstream side of the pipe in a moving direction in which the pipe moves from the first position to the second position, and
 wherein the seal is configured to contact an upstream side of the pipe in the moving direction of the pipe when the pipe is in the first position. 
 
     
     
       3. A cartridge according to  claim 1 , wherein the pipe has (i) a first end defining the opening and (ii) a second end opposite to the first end, and
 wherein the seal is configured to contact the second end of the pipe when the pipe is in the first position. 
 
     
     
       4. A cartridge according to  claim 1 , wherein the seal is fixed to the casing, and the pipe is configured to move away from the seal by moving from the first position to the second position. 
     
     
       5. A cartridge according to  claim 1 , wherein the pipe is a first pipe, and the casing includes a second pipe communicating the first pipe with the chamber, and
 wherein the first pipe is combined with the second pipe and movable along the second pipe between the first position and the second position. 
 
     
     
       6. A cartridge according to  claim 5 , wherein the first pipe surrounds the second pipe. 
     
     
       7. A cartridge according to  claim 5 , wherein the seal is configured to seal a gap between the first pipe and the second pipe. 
     
     
       8. A cartridge according to  claim 1 , wherein the chamber is a first chamber, and the casing includes a second chamber,
 wherein the cartridge further comprises:
 toner contained in the second chamber of the casing; and 
 a developing roller configured to develop a latent image formed on the photosensitive drum with the toner. 
 
 
     
     
       9. A cartridge according to  claim 1 , further comprising a movable shutter capable of opening and closing the opening of the pipe. 
     
     
       10. A cartridge according to  claim 9 , wherein the shutter is configured to prevent the pipe from moving from the first position to the second position when the shutter closes the opening of the pipe, and the shutter is configured to permit the pipe to move from the first position to the second position when the shutter opens the opening of the pipe. 
     
     
       11. A cartridge according to  claim 1 , wherein the seal is configured to be sandwiched between the pipe and the casing when the pipe is in the first position. 
     
     
       12. A cartridge according to  claim 11 , wherein the seal is compressed between the pipe and the casing when the pipe is in the first position. 
     
     
       13. A cartridge according to  claim 12 , wherein the compression of the seal, which is caused when the pipe is in the first position, is at least partly eliminated when the pipe is in the second position. 
     
     
       14. A cartridge according to  claim 1 , further comprising a cleaning blade contacting an outer peripheral surface of the photosensitive drum. 
     
     
       15. A cartridge according to  claim 1 , further comprising a rotatable coupling disposed adjacent to the opening of the pipe. 
     
     
       16. A cartridge according to  claim 15 , wherein at least a part of the coupling is disposed inside of the pipe. 
     
     
       17. A cartridge according to  claim 15 , wherein the coupling is configured to move with movement of the pipe between the first position and the second position. 
     
     
       18. A cartridge according to  claim 1 , wherein the seal is compressed between the pipe and the casing when the pipe is in the first position. 
     
     
       19. A cartridge according to  claim 18 , wherein the compression of the seal, which is caused when the pipe is in the first position, is at least partly eliminated when the pipe is in the second position.